Warmup:
Concept: OHM’s Law
Electrical current is a measure of the rate at which
electrical charge moves in a circuit. Electrical
current is measured in AMPERES. 1 Ampere is
equal to 1 unit of electrical charge (6.25x1018
electrons!) moving through a circuit in 1 second.
Electrical resistance is measured in Ohms.
Electrical resistance is caused by electrons bumping
into atoms as the electrons try to move on a wire
conductor. Electrical resistance is sort of like
electrical friction, it creates waste heat.
Voltage is electrical force. Voltage is caused by a
difference in charge between two points in a
circuit. Voltage is the force that moves electrons in
a circuit. Voltage is measured in volts.
OHM’s LAW:
V=I•R
V=I•R
In this equation “V” is voltage measured in volts, “I” is electrical
current measured in Amperes, and “R” is electrical resistance
measured in Ohm’s.
Q: What is the current in a circuit that has a
resistance of 300Ω and a voltage of 16.0V?
I=V/R
I= 16V/300Ω
I= .05A
The current is .05 Amperes
http://www.ndt-ed.org/EducationResources/HighSchool/Electricity/ohmslaw.htm